Two/three-dimensional (2/3D) multicellular constructs (MTCs), which consist of inter-connected and structurally organized cell populations, are widely used in various fields of regenerative medicine, biotechnology, and drug testing or development. For example, the patterns of electrical and mechanical activity in cardiomyocytes, and the coupling between them, are essential for normal functioning of the heart; their disruption usually signifies a diseased state. Cultured MTCs serve as models for studying electrical and mechanical properties of cardiac tissues in controlled conditions that replicate salient features of their natural environment, providing insight into the normal physiology and pathogenesis of heart diseases. In particular, they provide models for studying the mechanisms of cardiac arrhythmias and heart failure and serve as a tool for investigating the effects of molecular, genetic, pharmacological, and nonpharmacological interventions. However, technologies for noninvasive (nondestructive) functional evaluation of internal cell structures within such 2D and 3D MTCs are limited to X-ray microtomography (micro-CT) and a few other X-ray and ultrasound-based imaging modalities. Most of these methods do not provide high-quality soft-tissue characterization and often require injection of toxic substances for improved tissue contrast (“tagging”) (Perkel et al., 2012; Mizutani et al., 1993). In addition, the use of ionizing radiation in micro-CT and other X-ray based imaging is not appropriate for longer-duration, real-time functional imaging studies.